Vibration transducer assembly



Oct. 1952" s. M. BAGNQ ETAL VIBRATION TRANSDUCER ASSEMBLY Filed Dec. 9. 1948 firm/ems? Patented Oct. 7, 1952 UNITED STATES PATENT OFFICE VIBRATION TRANSDUCER/ASSEMBLY Samuel M. .Bagno, Astoria, and SidneyzL. Westere man, Great-Neck,.N. Y., assignors to The Alertronic Protective Corporationof America,,New York, N. Y., anorporation of New York ApplicationDecember 9, 1948,8erial No. 64,344

IOCIaiIhS. (Cl. 1'79--110)' The r present invention .rela-testo a' 4 vibration transducer assembly and more specifically .to one- Which is:active over fasubstantial:and'elongated area; v

By ;transducer"is meant an apparatus: which is capable of transforming r vibrations of one type of energy suchias electrical-tenergyflnto. correspondingsound vibrations, inthe manner of,a conventional loud speaker, or -,transformingreceived sound vibrations into correspondingvibrations ofsomeother type of energy suchaselectricalenergy in the. manner eta-conventional microphone;

Loudspeakers and microphones in common use act. as sound. generators or sound receivers only over :a limited'area. Thus, a conventional loudspeaker .is; provided with a. diaphragm f rela tively small area; the diaphragm .being vibrated to generate sound vibrations. The-sound is then transmitted through. a more or less complex acoustical path to an. enlarged outlet from which the sound emerges into the-rooms, Similarly; the diaphragm or other'sound-moved element of the microphone is of relatively small area, and an acoustical path defined by a horn or.-the-like .may. or may not be used in conjunction therewith. Themicrophone and loudspeaker therefore. act sub--- stantially =aspoint sources of sound. generation or sound reception. L

In many applications' this is a desirable characteristic, particularly when; :intelligencerin the form of sound is involved. l lowever there are" many applications in whiclrthe 1 S01E06 characteristic of these conventional transducers is not advantageous. F'or sexample, in the copending application, Ser. No. 776,368of Samuel M.

Bagno', filed September 26,.19e7 entitled Method i and; Apparatus for Detecting; Motion In a 'Cone fined Spaceandfassignedto i the assignee of the present invention, there-is disclosed a motion accomplished :only very, inefficiently; since there is a considerableloss-of energy involved-in-each. reflection, thedegree of vloss being dependent to n a large extent uponthe character of-=the surface.

from which refiection-takes place.=

It Would obviously be advantageous. in such could be generated in the room over --the entire Width thereof and if reception-.couldrbe similarly: achieved. .With such amethod otgeneration and reception; the-;-over-all efficiency of. the motion: detecting systemwould be greatly-increased. It is ap -prime object of the-present. invention to provide a vibration transducer assembly which--. acts as a vibration receiver orsender overarconsiderable or elongated areas It is another object of the present inventionto, devise such a transducereassembly which ,may be extended from wall to' wall of-zan enclosure-andoperate; as; a transducer over-substantially, its.-

. entire len th. 1

detecting system which depends for its efficient easily fabricated and assembled.- 1 1 l A still .further object ;of the present invention A further; object of the present.-invention is to devisesuch a transducer assemblyin-which the;-

vibration receiving or sending element also servesas the support for the transducer-itself. v 7

Yet another object of the present invention is to devisetransducer assembly in-which the,

vibration receiving or sending 1 element is inthe.-

form of i an elongated strip which may, besup- .4 ported atitsends and on which-1astransduce y.

may be mounted;

, An; additional. object of the'present invention 5 is to devise suchatransducer-assembly; the yarious elements-of Whichmayvbe inexpensively and is to devise such a transducer-assembly particularlyadapted foruse withamagnetostriction:type

transducer, said transducer being housedand connected to thervibration'receiving or sending element in ,a particularly convenient manner."

To. the accomplishment orthe foregoing; objects and such other obj ectsas mayrhereinafter appear; the present invention re'latesto alvibration trans-'- ducer assemblyas defined ins the appended claims and as described in this" specification; taken together with the. accompanying drawings;,-: in r.

Which:

Fig; 1' is aside view of one embodiment ofithe? transducer assembly T involving theemployment 1 system,that is to say, the reception 'of the .trans e mitted vibrations would be-accomplished-in a con-. siderably more efiicient mannensif-the vibrations could tie-generated inthe room by; an ;-element of considerable-or elongated :area.'. In particular it would be exceedinglyadvantageous-if vibrations- 1;:

agar-3328a jecting outfthrough 'the apertures 40in thefend's- 36 -a's2sliownin Figs: 1" and 21" Themagnetostrl'c tibn -rodf2l! is*then"slid through the *spools 26 and fastened to" its'supporting rod which may be attached to the bottom of-tlie housing-in any the lips 42 are bent upward along line ED 'at'right angles to h thelipsfl and "the ends of the magn'etost'ri'cti'on rod 20 are fastened thereto byany appropriate means. for 1 thehousing 28 if desired;

It will" be apparent-by the aboveconstruction that-as" the magnetostriction rod 20 contracts, it*will*'pu1l' the" upward extensions 48-01 the 'hous= ing rlips=42- toward one another; thustending'to' lift :the*- lips -42 and consequently" the portion of the ribbon 2 to'which the-lips are fastened by means of-rivets'46: As'therod 20 expands, mo'-- tion in theopposite direction takes place: The

portitms of-"the strip 2 towhich the lips-42 are fastened aretherefore moved up and down by variations in'the' le'ngthof'the rodZll and this motion in the direction of-thearrow I2 will be transmitted alongthe length of the'ribbon' 2,

causing that'ribbon tovibrate' in wave like form and thus act as a vibration sender oversubstan- A cover may 'be provided" induced by sound vibrations inuthe' ail-which the ribbon=2 picks up w-ill affect thermicrophone It! so as to transform the sound vibrations into corresponding electrical vibrations.

' It willbeapparent that the*=dimensions"ofthe elongated" element A maybe-"varied over "wide li'mits.- If "that elementtake'th'e' form of afrib bon; which is shown only in end view in Figs. 1-and'3; thethickness of that" ribbon will be 'the primary critical dimensionysinc'e'ifthe ribbon is t'oo' thick its-tendency-to vibrate the direction of the; arrows l2 orlS will b'e"materi.allyidiminished. Consequently, its" efiiciency as w a a, vibrationreceiver or sender'will be correspondingly destroyed; The width" ofthe ribbon is "n'otthe critical factor,"except"insofaras a ribbonof excessive: width" might notvibrate' in a uniform Y manner, and the length of "the'ribbonmay be made "as long as" desired "consistent with maintainingsuflic'ient'tension onthe ribbon toper-mit rod 20 and the ribbon 2 for vibration of the latter. 7 r The transducer assembly of the present invention has the prime advantage that it receives or sends vibrations over a substantial area, and in particular over an elongated area, even if conventional vibration generators or microphones are employed, which vibration generators or microphones normally have a point-source char- 6* acteris'tictorr1atther verymost a hi'ghly: lo'ealizedfi; sourcecharacteristic; The eflect: of combininge' a conventional" vibration generator? or miCruiphone with the I eleg'onatedl element Au OfLTthif? present invention is 'to form a vibration trans?- ducer assemblywhich is 'the equivalent of aninsfinite number of conventionalltransducers'placedi side by-side "alongthexlength" of the elongatedil element A.-- This assembly therefdre constitutese an extremely-*eificient' and inexpensive means 'ifOI'JL transmitting Or -receiving sound over atwidet'area and in-'particular for "filling an enclosed?spasm with vibrations. This transducer assembly 1 is: simp'le of construction, beingz'composedit'oi a larger: degree of conventional elementsr' and thez-f'non'econventional elements of Iwhich make:.:for l simplicity and inexpensivenessrof manufactures BYE notonly operatively iconnectingithe itransducen:

B and i the elongated :element' Abut by; supportin then-former on theslatter; a unitary. structure achieved-which attains: all of: thei 'above iadvans tages."

It :will :be appreciated that;.:many"variations? may be maderinithe"details'iof thez-zconstructionl of tliex transducer? assembly "without? departingl from'nthe "spirit of the. invention"astdefiriedi'inithei appended claims:

We rclaim'zx i r 1. A vibration: generator" assembly; comprising; a thin', narrow #elongat'ed istripi' supported. ati'botii ends'i'and' capable of ivibration inLa: dlrectionr'pene pendicularx." to itsl lengthy" a1: magnetostrictionz: transducer housing; lips omsaidhousing oriented; in the 1 direction: of said strip 1 and? connected theretoiat points spaced alongr-the 'length' of said strip; at least onerof said.pointszbeingspaced:farm inwardly from an end 'ofJ-sai'd strip; a magneto,- striction coil in said housing, a magnetostric'ti'on rod" inside said coil and oriented in the directions of said 1 strip;- the endsof said rod projecting-from said housing and overlying said housin'gdips; and connectionsbetweensthe ends of sai'drod and said lipsglwhereb'ycontractibns and expansionsi'of said-" 5 rod set up the 'vibra'tions in -saidlstrip;= said "strip thus acting as a vib'ration senderover substan tially its-'entire'length;

2? The vibration generator assembly of'blaim'd in which said connections comprise' upward 'ex tensions of said lips-to which the ends-nf 'said'rod are iastened.-

3. Thee-vibration-generator assemblyof"- *clainr: 1, in which said connections comprise-"integral upward extensions of said lips to whichwhe ends' of said rod are fastened 4. A-housing for a-magnetostrictivetransducers comprising an enclosure including "bottom and "i endwalls, said end-wallshaving apertures 'there 1' through and said bottom wall having lips'.'ex=' tending longitudinally from said enclosure means: on'said lips forsecuring said housin'g to-amex ternal vibratory-element, and upwardextnsions' from said lips and in line with said apertures.

5. A one-piece housing for a magnetostrictive transducer comprising an enclosure formed from a single sheet of material and including bottom and end walls, said end walls having apertures therethrough and said bottom wall having lips extending longitudinally from said enclosure. means on said lips for securing said housing to an external vibratory element, and upward extensions from and integral with said lips and in line with said apertures.

6. A vibration transducing system for operating in the supersonic range comprising walls surrounding an elongated space which is to be sub- 7% stantially filled with vibrations, and a-transducer assembly -mounted between said walls, said assembly; comprising: an elongated element exof: energy or vice versa, said elongated; element thus-acting. as a vibration receiver or sender over substantially its entire length and efiiciently filling saidispace; \withgs-vibrations ore-detecting:

vibrations therein, as the case may be. L 1

--7'.-A vibration transducingv'system for operating inthe supersonic range comprising walls surroundingaan elongated space which is to be substantially filled with vibrations, anda transducer assembly mounted between said walls; said assembly comprising an elongated ribbon-like ele-. ment'substantially fiat in its width and extendingv'lengthwise substantially; from one end to theother vof said spaceflsaid element-being capableof vibrating in a given direction substantially. atiright angles to its length and width at frequencies in the supersonic range, and a transducer operatively connected to said elongated elementlso as to convert vibrations thereof into another formvof energy or vice;versa,-said elongatedelementathus acting as 'afivibration receiver or senders-over substantially its entire length and efliciently filling said space with vibrations or detecting vibrations therein, as the case may be.

8. A vibration ,transducing system for operating. in thessupersonic range comprising walls surrounding. an elongated space which is to be substantially filled with vibrations, and a transducer assembly-mounted between-said walls, said assembly comprising an elongated element extends ing substantially from oneend to the other of said spacegsaid element being. capable of vibrating in a givendirection substantially at right angles to its length and width at frequencies in the supersonic range, and a transducer mounted on and supported by said elongated element and operativelyconnected thereto so as to convert vibrations thereof into another form of energy or vice'versa, saidelongated element thus acting as a vibration receiver or sender over substantially its entire lengthand efficiently filling said space with vibrations-or detecting vibrations therein, as thecase maybe. 2

9. A vibration transducing-system for operation in the supersonic range comprising walls surrounding an elongated spacewhich is to be substantially filled with vibrations, and a, transducer assembly" mounted between said-walls, said assemblycomprising 7 an elongated element extendingsubstantially from one end to the other of said. space, said element being capable of vibrating in a given direction substantially at right angles to its .length and width at frequenciesin the supersonic range,- and acrystal transducer, mounted on and supported by said elongated-ele-. ment and operatively connected thereto so as to convert vibrations thereof into another-form of energy or vice versa, said elongated element-thus acting as a vibration receiver or sender over substantially its entire length and efficiently filling said space with-vibrations or detecting vibrations therein, as'the case maybe. f T

10. A. vi-bration transducing system for'operating in the supersonic range comprising-Walls surrounding an elongated; space which is to be substantially filled withvvibratiomanda transducer assembly mounted between said walls, said assembly comprising an elongated element extendmg substantiallyfromone end to the other of said space, said element being capable ofvibrating in a given; direction substantially at right angles to its length and width at frequencies in the super-- son c range,- and a magnetostriction transducermounted on and supported by said elongated element and-operatively connectedthereto so as-to convert vibrations thereof into another form ofv energy or vice versagsaid elongated element thusacting as-z-a vibration receivervor sender over substantiallyits entire length and efliciently filling. sa d space with vibrations or detecting, vibrations therein,.as thecase may be; r SAMUEL M. mono.

SIDNEY L. WESTERMAN- v 'R NCE o L The :following references "are of record in the file of this patent: -j r ,g

g UNITED ATE PATENT '8 Number Name 339,500. Thompson, Apr. 6,-f1886 351,905 1 aickemeyertrun uc Nov. 2,1886 1,033,788 5 Adams-Randall 1 Jan.-6, 1914\- 1,213,17-e1 Fessenden Jan; 23,19'1'7 1,213,610 ,Fessenden ---Jan.=23, 1917f 1,405,349 'Kohlhaas Feb '1, 19221 1 ',e21,'5s2 Staunton," -Mar. 22- 192i 1,854,025 Fessenden Apr; 12, 1932 1,863,840 ,Fessenden 31111621, 1932' 1,873,715 7 Me'is sner Au 'zs, 1932i; 1,882,401J 7 Pierce 1 v "oct. -11,'.19'3'2. 1,919,632 Ha1gis i Ju1 1'25,.f1'933. 2,064,911 Hayes Dec. '22, 19361 2,168,809 'Semple Aug. a 1939 2,169,744; 7 Sears Aug. 15"19'39 2,257,995 Abrams et a1 Oct. 7f 1941 2,345,7711 "Reynolds 'A r.'.4, 11944- 2,391,678 Bundy De'c.'25 1945 2,403,503 1 .Coulter July '9"194s 2,459,102 Adair" Jan. 11: 1949 

